Migraine and cochlear disease: A 2-sample bidirectional Mendelian randomized study

This study aimed to explore the potential causal relationship between migraine and cochlear disease by using a bidirectional Mendelian randomization (MR) approach. We searched datasets related to migraine in the FinnGen database and genome-wide association studies catalog. We conducted 2-sample MR analyses. Instrumental variables were selected based on stringent criteria, including genome-wide significance, clumping to ensure independence, and exclusion of palindromic single nucleotide polymorphisms and those associated with confounders. The primary MR analysis employed the inverse-variance weighted (IVW) method supplemented by sensitivity analyses using the Weighted Median and MR-Egger (MR-Egger) methods to address potential pleiotropy. MR analyses suggested a causal relationship between migraine and increased risk of cochlear disease. MR analyses suggested that migraine was associated with an increase in tinnitus (IVWMR odds ratio (OR) = 1.516, 95% confidence interval (CI): 1.064-2.159, P = .021). Migraine was also associated with an increase in vertigo (IVW MR OR = 1.631, 95% CI: 1.003-2.651, P = .049). Medication use (antimigraine preparations) was associated with an increase in sudden idiopathic hearing loss (IVW MR OR = 1.187, 95% CI: 1.023-1.378, P = .024). Medication use (antimigraine preparations) was also associated with an increase in other hearing loss (IVW MR OR = 1.085, 95% CI: 1.007-1.169, P = .032). Migraine with no aura triptan was associated with an increase in tinnitus (IVW MR OR = 1.226, 95% CI: 1.075-1.398, P = .002). These findings were robust across various sensitivity analyses, including MR-Egger and MR Pleiotropy RESidual Sum and Outlier, supporting the absence of pleiotropy and outliers. Our results establish a causal link between migraine and cochlear disease, indicating that migraine may exacerbate cochlear disease. Additionally, these findings strengthen the evidence-based medical foundation of the relationship between migraines and cochlear disease. They offer theoretical support for future migraine aimed at treating cochlear disease.